The present embodiments relate to multidimensional transducer arrays. In particular, a multidimensional transducer array interconnects with electronics used for imaging.
Achieving the interconnection between an acoustic array and the associated transmit and/or receive electronics is a key technological challenge for multidimensional (matrix) transducers. Hundreds or thousands of different elements distributed in two dimensions (azimuth and elevation) require interconnection along the z-axis (depth or range) for at least the elements surrounded by other elements. Since the elements are small (e.g., 250 um), there is limited space for separate electrical connection to each element.
In U.S. Pat. No. 8,754,574, a modular approach is used. For each module, a flex circuit with traces is positioned to connect to some of the elements. To accommodate other modules to connect with other elements, the flex circuit folds over a mechanical substrate or frame. Since the signal traces are confined to one or two surfaces of the flex circuit, the trace density is very high, limiting the size of arrays that can be practically assembled and resulting in electrical cross-talk. The flatness of the laminated assembly of modules must be held to very high tolerance (e.g. +/−2 um corner to corner and along seams). If the surface from laminated modules is out-of-tolerance, correction is not possible and the piece is discarded. The assembly is particularly subject to failures along the lamination lines due to a very tight flex-circuit radius of curvature to allow positioning of other modules. The flex circuit interrupts thermal conduction from the array. There is no straight path for heat to conduct from the array into the frame of the module because all conductors are on the surface of the flex circuit (perpendicular to the desired heat path). Other approaches for multidimensional interconnection suffer from problems of volume, parasitic capacitance, crosstalk, thermal efficiency, manufacturing, and/or electronic packing density.